I think you answered your own question quite well with your quote.
when looking for an original game idea, don't look to games, but look to your own experiences and other forms of media.
When there is no relatable content within the genre of media you're examining its best to look elsewhere (other forms of media) as well as within your own experiences.
Da Vinci found motivation in everything he witnessed and examined. This day and age we are jaded due to all the information that is readily available. We shouldn't have to look beyond ourselves to find inspiration in what we observe and experience.